1. Technical Field
An aspect of the present disclosure generally relates to a memory device and a manufacturing method thereof, and more particularly to a three-dimensional memory device and a manufacturing method thereof.
2. Related Art
A memory system may include a memory device for storing data and a memory controller for controlling the memory device.
Examples of the memory device may include a volatile memory device and a nonvolatile memory. The volatile memory device is a memory device that only retains its data while it is powered. The nonvolatile memory is a memory device that can retain its data even in the absence of a power source.
As portable electronic devices are widely used, nonvolatile memory devices are widely used as data storage devices.
Among nonvolatile memory devices, flash memory devices are frequently used in portable electronic devices.
A flash memory device may include a memory cell array for storing data, peripheral circuits for performing program, read, and erase operations, and a control logic for controlling the peripheral circuits.
For example, a memory cell array of NAND flash memory device may include a plurality of memory blocks, and each of the memory blocks may include a plurality of memory cell strings. Memory devices may be classified into two-dimensional and three-dimensional memory devices depending on structures of memory cell strings.
A two-dimensional memory device may include memory cell strings horizontally arranged over a substrate, and a three-dimensional memory device may include memory cell strings vertically arranged from a substrate.